parseLiteral example

            $part->addName($name);
        }
        $this->consumeWhitespaces();
        $operator = $this->consumeAny($this->attrOperatorChars);
        if ($operator) {
            if (!in_array($operator, $this->attrOperators)) {
                throw new Exception("Invalid attribute operator '$operator'");
            }
            $part->setOperator($operator);
            $this->consumeWhitespaces();
            if (!($value = $this->parseLiteral())) {
                throw new Exception("Missing attribute value");
            }
            $part->setValue($value[0]);
            if ($value[1]) {
                if ($operator != "=") {
                    throw new Exception(
                        "Only '=' operator is valid for attribute regex match"
                    );
                }
                $part->setRegex(true);
            }
            

protected function parsePrimaryExpression()
    {
        if ($token = $this->scanner->consume("this")) {
            $node = $this->createNode("ThisExpression", $token);
            return $this->completeNode($node);
        } elseif ($exp = $this->parseFunctionOrGeneratorExpression()) {
            return $exp;
        } elseif ($exp = $this->parseClassExpression()) {
            return $exp;
        } elseif ($exp = $this->parseIdentifier(static::$identifierReference)) {
            return $exp;
        } elseif ($exp = $this->parseLiteral()) {
            return $exp;
        } elseif ($exp = $this->parseArrayLiteral()) {
            return $exp;
        } elseif ($exp = $this->parseObjectLiteral()) {
            return $exp;
        } elseif ($exp = $this->parseRegularExpressionLiteral()) {
            return $exp;
        } elseif ($exp = $this->parseTemplateLiteral()) {
            return $exp;
        } elseif ($this->jsx && ($exp = $this->parseJSXFragment())) {
            return $exp;
        }